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storage: Manually expand `genericAdd` for specific types

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This commit is doing what I would have expected that Go generics do
for me. However, the PromQL benchmarks show a significant runtime and
allocation increase with `genericAdd`, so this replaces it with
hand-coded non-generic versions of it.

Signed-off-by: beorn7 <beorn@grafana.com>
pull/11687/head
beorn7 2 years ago
parent 551de0346f
commit 717a3f8e25
1 changed files with 179 additions and 13 deletions
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192
storage/buffer.go
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@ -401,17 +401,17 @@ func (r *sampleRing) add(s tsdbutil.Sample) {
switch s := s.(type) {
case fSample:
if len(r.hBuf)+len(r.fhBuf) == 0 {
r.fBuf = genericAdd(s, r.fBuf, r)
r.fBuf = addF(s, r.fBuf, r)
return
}
case hSample:
if len(r.fBuf)+len(r.fhBuf) == 0 {
r.hBuf = genericAdd(s, r.hBuf, r)
r.hBuf = addH(s, r.hBuf, r)
return
}
case fhSample:
if len(r.fBuf)+len(r.hBuf) == 0 {
r.fhBuf = genericAdd(s, r.fhBuf, r)
r.fhBuf = addFH(s, r.fhBuf, r)
return
}
}
@ -435,7 +435,7 @@ func (r *sampleRing) add(s tsdbutil.Sample) {
r.fhBuf = nil
}
}
r.buf = genericAdd(s, r.buf, r)
r.buf = addSample(s, r.buf, r)
}
// addF is a version of the add method specialized for fSample.
@ -443,13 +443,13 @@ func (r *sampleRing) addF(s fSample) {
switch {
case len(r.buf) > 0:
// Already have interface samples. Add to the interface buf.
r.buf = genericAdd[tsdbutil.Sample](s, r.buf, r)
r.buf = addSample(s, r.buf, r)
case len(r.hBuf)+len(r.fhBuf) > 0:
// Already have specialized samples that are not fSamples.
// Need to call the checked add method for conversion.
r.add(s)
default:
r.fBuf = genericAdd(s, r.fBuf, r)
r.fBuf = addF(s, r.fBuf, r)
}
}
@ -458,13 +458,13 @@ func (r *sampleRing) addH(s hSample) {
switch {
case len(r.buf) > 0:
// Already have interface samples. Add to the interface buf.
r.buf = genericAdd[tsdbutil.Sample](s, r.buf, r)
r.buf = addSample(s, r.buf, r)
case len(r.fBuf)+len(r.fhBuf) > 0:
// Already have samples that are not hSamples.
// Need to call the checked add method for conversion.
r.add(s)
default:
r.hBuf = genericAdd(s, r.hBuf, r)
r.hBuf = addH(s, r.hBuf, r)
}
}
@ -473,25 +473,191 @@ func (r *sampleRing) addFH(s fhSample) {
switch {
case len(r.buf) > 0:
// Already have interface samples. Add to the interface buf.
r.buf = genericAdd[tsdbutil.Sample](s, r.buf, r)
r.buf = addSample(s, r.buf, r)
case len(r.fBuf)+len(r.hBuf) > 0:
// Already have samples that are not fhSamples.
// Need to call the checked add method for conversion.
r.add(s)
default:
r.fhBuf = genericAdd(s, r.fhBuf, r)
r.fhBuf = addFH(s, r.fhBuf, r)
}
}
func genericAdd[T tsdbutil.Sample](s T, buf []T, r *sampleRing) []T {
// genericAdd is a generic implementation of adding a tsdbutil.Sample
// implementation to a buffer of a sample ring. However, the Go compiler
// currently (go1.20) decides to not expand the code during compile time, but
// creates dynamic code to handle the different types. That has a significant
// overhead during runtime, noticeable in PromQL benchmarks. For example, the
// "RangeQuery/expr=rate(a_hundred[1d]),steps=.*" benchmarks show about 7%
// longer runtime, 9% higher allocation size, and 10% more allocations.
// Therefore, genericAdd has been manually implemented for all the types
// (addSample, addF, addH, addFH) below.
//
// func genericAdd[T tsdbutil.Sample](s T, buf []T, r *sampleRing) []T {
// l := len(buf)
// // Grow the ring buffer if it fits no more elements.
// if l == 0 {
// buf = make([]T, 16)
// l = 16
// }
// if l == r.l {
// newBuf := make([]T, 2*l)
// copy(newBuf[l+r.f:], buf[r.f:])
// copy(newBuf, buf[:r.f])
//
// buf = newBuf
// r.i = r.f
// r.f += l
// l = 2 * l
// } else {
// r.i++
// if r.i >= l {
// r.i -= l
// }
// }
//
// buf[r.i] = s
// r.l++
//
// // Free head of the buffer of samples that just fell out of the range.
// tmin := s.T() - r.delta
// for buf[r.f].T() < tmin {
// r.f++
// if r.f >= l {
// r.f -= l
// }
// r.l--
// }
// return buf
// }
// addSample is a handcoded specialization of genericAdd (see above).
func addSample(s tsdbutil.Sample, buf []tsdbutil.Sample, r *sampleRing) []tsdbutil.Sample {
l := len(buf)
// Grow the ring buffer if it fits no more elements.
if l == 0 {
buf = make([]tsdbutil.Sample, 16)
l = 16
}
if l == r.l {
newBuf := make([]tsdbutil.Sample, 2*l)
copy(newBuf[l+r.f:], buf[r.f:])
copy(newBuf, buf[:r.f])
buf = newBuf
r.i = r.f
r.f += l
l = 2 * l
} else {
r.i++
if r.i >= l {
r.i -= l
}
}
buf[r.i] = s
r.l++
// Free head of the buffer of samples that just fell out of the range.
tmin := s.T() - r.delta
for buf[r.f].T() < tmin {
r.f++
if r.f >= l {
r.f -= l
}
r.l--
}
return buf
}
// addF is a handcoded specialization of genericAdd (see above).
func addF(s fSample, buf []fSample, r *sampleRing) []fSample {
l := len(buf)
// Grow the ring buffer if it fits no more elements.
if l == 0 {
buf = make([]fSample, 16)
l = 16
}
if l == r.l {
newBuf := make([]fSample, 2*l)
copy(newBuf[l+r.f:], buf[r.f:])
copy(newBuf, buf[:r.f])
buf = newBuf
r.i = r.f
r.f += l
l = 2 * l
} else {
r.i++
if r.i >= l {
r.i -= l
}
}
buf[r.i] = s
r.l++
// Free head of the buffer of samples that just fell out of the range.
tmin := s.T() - r.delta
for buf[r.f].T() < tmin {
r.f++
if r.f >= l {
r.f -= l
}
r.l--
}
return buf
}
// addH is a handcoded specialization of genericAdd (see above).
func addH(s hSample, buf []hSample, r *sampleRing) []hSample {
l := len(buf)
// Grow the ring buffer if it fits no more elements.
if l == 0 {
buf = make([]hSample, 16)
l = 16
}
if l == r.l {
newBuf := make([]hSample, 2*l)
copy(newBuf[l+r.f:], buf[r.f:])
copy(newBuf, buf[:r.f])
buf = newBuf
r.i = r.f
r.f += l
l = 2 * l
} else {
r.i++
if r.i >= l {
r.i -= l
}
}
buf[r.i] = s
r.l++
// Free head of the buffer of samples that just fell out of the range.
tmin := s.T() - r.delta
for buf[r.f].T() < tmin {
r.f++
if r.f >= l {
r.f -= l
}
r.l--
}
return buf
}
// addFH is a handcoded specialization of genericAdd (see above).
func addFH(s fhSample, buf []fhSample, r *sampleRing) []fhSample {
l := len(buf)
// Grow the ring buffer if it fits no more elements.
if l == 0 {
buf = make([]T, 16)
buf = make([]fhSample, 16)
l = 16
}
if l == r.l {
newBuf := make([]T, 2*l)
newBuf := make([]fhSample, 2*l)
copy(newBuf[l+r.f:], buf[r.f:])
copy(newBuf, buf[:r.f])

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